Over the past several years, our research has focused on physiological changes in cortical and spinal motor circuits in patients with primary lateral sclerosis (PLS). In collaborative studies with Dr. Ou Bai, we identified oscillatory EEG signals that preceded movement in PLS patients in whom the slow DC potentials generated by cortical neurons were diminished. In FY08, we report that single-trial changes in these oscillatory signals with imagined movement can provide a control signal for an EEG-based brain-computer interface in a small number of PLS patients. This work is being extended to amyotrophic lateral sclerosis (ALS) patients in the coming year. A second line of study is aimed at assessing the extent of (non-motor) frontal cortical dysfunction in PLS patients, and to compare them to patients with ALS. This 3-year protocol includes neuropsychological tests, psychiatric assessment, and quantitative MRI imaging, and is in its second year. Lastly, recognizing that PLS is likely to be complex disorder, we are collecting samples from PLS patients for the NINDS DNA repository for motor neuron diseases at Coriell, so that this rare population will be accessible to the general scientific community for further studies.